I'm having a few problems with my Dell PC.
Basically, when I turn it on, it boots normally. However, in less than 5 minutes, the two monitors either turn a solid colour or vertical stripes appear, causing the computer to be completely unresponsive (ie ctrl-alt-del does nothing, the keyboard lights go off, etc). After forcing a restart, the fans and hard drive spin but there are no beep codes and the monitors remain blank. Windows will finally load after about another 4 reboots, and if the whole cycle doesn't start again, it is fine and I can use it normally for many hours.
I usually use the onboard graphics (ATI Radeon HD 3200) but my pci-e NVIDIA GeForce 9400 card causes the same problems, except with a frozen screen instead of the solid colour or stripes. Also, changing the PSU made no difference.
Possibly related to the first problem, I have noticed that the sound seems to become distorted after leaving it on for a while, even though my speakers worn fine with other devices.
I am running Windows 7 Ultimate 32-bit in a dual boot configuration with Windows XP MCE, on an AMD Athlon 64 X2 5400 processor with 4GB RAM.
I hope someone can help me - as it is, it is virtually unusable. :(